Dental floss holder



FIG. 1 is a perspective view of a dental floss holder showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a bottom plan view thereof.

The broken lines are shown for illustrative purposes only and form no part of the claimed design. 

The ornamental design for a dental floss holder, as shown and described. 